Aladan, that Serge module looks awesome. It seems like it would be better suited for a modular synth though, since I'm going to be using switches for my routing. I have to be choosy about how components interact or I'll end up with too many switches. However, when this project is complete, I had planned on an extension for my Sound Lab Ultimate, so that looks like it would fit in nicely.

All of the boards, minus the mixer and noise section, are now fully populated. Keyboard has been populated with a 0.1% resistor chain. Power supply has been tested out OK. All other boards need to be tested. A layout has been created in Adobe InDesign. Glide and Ribbon Controller settings are going to be on the modulation board (when I get there). That will probably be the last thing I do, since I have to source a bender board.

The way I do my panels cheaply is to get a sheet of rigid plexi ($20) and spray mount the laser printed design onto the inside facing up. Then I spray mount a sheet of aluminum foil to the back of that for shielding. The glue makes it look a little bit foggy, but it prevents it from ripping up or scratching off because it's on the inside. You just have to be extra careful when drilling the holes and tightening the pots so that you don't crack it. I drill in 3 steps/sizes. I don't gig with this gear, so I have no concerns for it getting damaged/cracked from transport._________________The Phoenix Vertigo is my Electronic alias. Check out my songs on soundcloud : http://soundcloud.com/charles-stieg/

One suggestion - I would add a couple of pots (in between the two VCOs if you can fit them) to allow modulating VCO1 with VCO2, and to mod VCO2 with one of the envelopes (especially if you want that 'sync sweep' sound). Maybe find some pots with nice looking plastic shafts so you don't need a knob (look at the Fine Tune pots on the new Oberheim SEM). I'm basically thinking you'll be happier if you throw a few more modulation options in there. Maybe even add some I/O jacks along the bottom? Oh, and maybe be able to trigger one or both of the envelopes with the LFOs.

I am a violator of opening a old thread!! Sorry. But I just wanted to thank everyone for helping out and offering suggestions to me. This community is one of my favorite places on the internet!!! You have all definitely helped with the development of my custom synth. I had a kid recently, which suspended any work on this project for a good 4+ months, but I'm back and ready to complete it (hopefully). Currently, the biggest hurdle has been the Yusynth minimoog VCF misbehaving. For whatever reason, it does not want to filter properly unless the resonsnace is cranked, even with a mixer/buffer behind it. I've lost hope with it. Running 12+/- V and have made appropriate resistor calculations to allow it to function that way too. I'm at the point where I'm probably going to just ditch the minimoog filter and build Ray Wilson's 24 dB filter and see how that works. The Roland 130 VCA and 140 Envelope generator layouts by Frequency Central work like a charm though. Nice and snappy, and have all the charm of my SH-101. Can't thank him enough for them. I totally understand the time and commitment to creating something like that, so cudos to you Frequency Central! I'm at the homestrech now, and I'm going to test out the sub-osc freq/divider circuit via 4024 logic circuit tonight ( I even left the lower divisions as a route to the LFO), as well as the noise circuitry based off of Ray Wilson's noise generator. As long as I'm not idiotic enough, maybe I'll even finish this thing.

Very soon, as soon as I get the VCA issues figured out. Then I've gotta get the noise section and magic smoke LFOs functioning. Did manage to get the logic sub circuit to function externally processing a signal, although it will be tricky being that it only functions on the v+ rail. I am learning this as I go through it so it is quite difficult for me to understand everything involved with the switching. My board layout didn't have the exp/lin switch and DC/AC DPDT involved with the vca, and I'm also having trouble figuring out how to wire the switches. My first attempt tonight was unsuccessful, but it probably has to do with the FET pin outs. Waiting for frequency central to elaborate on that one before I proceed any further. I am sort of at the point where I may convert the whole thing to a modular patch system, as it would be a hell of a lot easier to debug if I abandoned the switching and went with banana plugs. Scoping stuff out right now is a nightmare because of the interactions with all of the voltage rails and grounding. I think the best idea would be to abandon the hard wiring of the power circuit and installed crimped power connections to I could disable anything interacting with it right now. I am pretty obsessive though so I'm sure I'll figure it out eventually._________________The Phoenix Vertigo is my Electronic alias. Check out my songs on soundcloud : http://soundcloud.com/charles-stieg/

I definitely like the idea of a filter with band and high pass filtering options. SOOOooo.. I actually ditched the minimoog filter after getting annoyed with it, built a MFOS 24db vcf AND I'm building another 12db L/B/H vcf for it, with the option of running voices through either or both.... This is quickly turning more into a modular synth! I really wanted to keep it neat and simple with switches, since I already have a soundlab ultimate with endless sound mangling options, but the more ideas I come up with, the more switches get added to the layout, and I love the idea of simultaneous filters with the voices, gives so many more options soundwise. Still, I believe less is more, so I'll probably ditch a lot of the bells and whistles int he final layout and keep what I like most. I'll post an update when I'm there._________________The Phoenix Vertigo is my Electronic alias. Check out my songs on soundcloud : http://soundcloud.com/charles-stieg/

Cool, I'd love to see the guts of yours. I think its a fun idea to have a custom self-contained synth. I love modular synths, but far too often synth junkies focus on all of the possibilities of having endless modules instead of the less is more approach. Hence the reason why I spend 10x more time using my SH-101 than my Prophet 08.

I gave up on the YuSynth Minimoog filter because I could not get it to behave properly. I would not get any kind of decent output without having the res. cranked fully, despite what kind of gain settings I had on it. I even replaced multiple resistors with trimmers, but it didn't play nice with the other components I built._________________The Phoenix Vertigo is my Electronic alias. Check out my songs on soundcloud : http://soundcloud.com/charles-stieg/

You are so right
It happens to me as well, when I play with my synths some times I lose the my self and dive into endless dapath of sounds.
I cry every day for selling my sh101 especeially after mod is ass

That's some nice synth-porn you have there. I like the old case too. And great choices in modules. I've built a valvecaster and I use it to process vocals, drums, and whatever else I wanna mangle on recordings, sounds disgusting too! I always wanted a bug crusher, but couldn't source that chip for it easily.

You should start a new thread for your project so people can track it. The one thing I never got the hang of that you definitely do is cleanliness. My synth is a rat's nest, and the boards I etched look like crap, but at least they work fine. I'm more about trying to build stuff with what I have available too, so I'll substitute parts and values and whatnot and mix/match things to avoid having to place a small parts order. I even base what I'm building on what I have laying around usually. There are some good and bad results from that practice obviously, but I've had some delightful ones with certain projects. Just got into lunettas too, so I finally have some use for the 60+ 4000 logic series chips I have laying around from repair jobs._________________The Phoenix Vertigo is my Electronic alias. Check out my songs on soundcloud : http://soundcloud.com/charles-stieg/

I got the front panel drilled, just need to install all the pots and switches. I changed the VCO outs to a waveform selector switch, and added a drill hole by the VCF for filter tracking (forgot in the panel layout). Also forgot to add the routing description on the layout for VCO PWM on the LFO selector, I'll probably just add a little sticker for it on the panel and one the VCF filter tracking knob. I decided to stick to a single filter, if I do ever want to do band pass/high pass I'll just do it with plug-in within my DAW. Here's what's inside, all boards are nearly completed, just wating for 5m resistors for the LFOs, wiring up a 2n3904 LED indicator for both of them, debugging the one of the VCOs bleeding into the noise section, and debug partially working VCA (got some distortion in the signal).
1 x MFOS bipolar power supply
2 x MFOS VCOs
1 x MFOS 24dB/oct VCF
1 x FreqCentral's Roland 130 VCA
2 x FreqCentral's Roland 140 ADSR
2 x Magic Smoke LFOs
1 x MFOS White noise generator (section from Soundlab Ultimate)
1 x MFOS Mixer (section from Soundlab Ultimate)
1 x Sub Oscillator (4024 section from SH-101) - Still need to finish build

VCA is now working. I had ordered 10 CA3080e's off of eBay (China), and low and behold, they don't work properly. I had pulled a RCA CA3080 from my stepdad's OB-Xa when I was doing repairs on it that I popped in there (non "E" marked CA3080) and now I don't have the issues with the distorted output and improperly functioning initial volume pot. I had similar issues with that repair in that the replacement CA3080e's I bought disabled the master volume pot and screwed up the output stage (VCA initial gain stage pot), so I should have remembered that repair and tossed them out. I assumed at first that the signal was just too weak or too hot going into the VCA because of the combination of modules I was using, but after measuring voltages and mA in the scope, it was definitely exactly where it needed to be.

On a hunch, I decided to bust out the non-functioning YuSynth Minimoog VCF I built for this project that had CA3046's I also purchased off of eBay, swapped out those two ICs with two RCA ones I pulled out of a non-working Moog MG-1 a while back, and now that module works as well. Go figure.

So the moral of the story is DON'T BUY ICs off of eBay from China. I had previously bought a batch of LM13700s that work great, so I had just assumed that I'd be lucky with these other OTAs. Since the LM13700s are still available it is unlikely that they're going to waste the time to sand & rebrand fake ICs for them. I just figured I'd put out a warning to other buyers not to waste their money on these.

I also fixed the VCO bleed with a bit of TLC, did some lead-dressing and fixed the grounding scheme to remove a ground loop. All that is left is to finish the Sub oscillator board, clean up/wire tie the rats nest inside, glue the LEDs in place, fix a couple of poorly triggering j-wires on my keyboard, build two side wood panels to cover the keyboard, and make a panel for the ON/OFF switch, power jack, CV inputs, external input jack and output jack. The left side will be home to the glide pot, indicator LEDs, trigger/gate switch, and mod pots/switches I plan on throwing in there. Sound clips and video will follow.

Somewhere down the line I will install at ribbon controller like on the Yamaha CS80 with CV pitch control using the sample & hold circuit on PAiA's website (already built this a while back and it works great) and I already have a spring-loaded pot ready to install on the control board (left side) to send CV to the VCA (sorta like the French Connection controller). Makes it nice and easy to control the volume.

The sellers for the parts I received that did not work were goodbuy711 (despite the 99.8% positive rating) and jorgeospina83_________________The Phoenix Vertigo is my Electronic alias. Check out my songs on soundcloud : http://soundcloud.com/charles-stieg/Last edited by defog on Sun Feb 10, 2013 8:48 pm; edited 2 times in total

Yah, my policy has been to avoid chinese silicon unless there's no other source, and think hard even so.

MN3005's are another type that are almost guaranteed to be fake/wrong from Hong Kong.

Looks like you can get 3080's from Mammoth Electronics for $4 each. There's also a CoolAudio clone but I don't know who carries them.

I have a few but I am not having any luck finding where I bought them from....

I had no idea cool audio was cloning those. Cudos to them, the delay line chips they make are superb and I've used them in a number of stop-box projects (delay, chorus, vibrato)._________________The Phoenix Vertigo is my Electronic alias. Check out my songs on soundcloud : http://soundcloud.com/charles-stieg/

Sorry to hear about what you've gone through.
It's not true to say all the Chinese eBay sellers sucks.
You just need to find the good ones
I'm very happy with mine.

Cheers and hope everything will be ok for you.

I hear ya, but I think I've dealt with enough headaches with these 3 issues to warrant trying my luck again. I'll just stick to small bear and mouser from now on._________________The Phoenix Vertigo is my Electronic alias. Check out my songs on soundcloud : http://soundcloud.com/charles-stieg/

I've since moved this to a non-dedicated keyboard controller enclosure to save space. I haven't build the woodwork for it yet, but the face plate is fully populated and running, minus the LFOs and some other features I plan to add to it (Delay FX, Feedback loop, etc.)._________________The Phoenix Vertigo is my Electronic alias. Check out my songs on soundcloud : http://soundcloud.com/charles-stieg/

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